Submission #1041853

#	Time	Username	Problem	Language	Result	Execution time	Memory
1041853		MMihalev	Beads and wires (APIO14_beads)	C++14	0 / 100	1 ms	604 KiB

beads

#include<iostream>
#include<algorithm>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<vector>
#include<queue>
#include<stack>
#include<tuple>
#include<set>
#include<map>
#include<random>
#include<chrono>
#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
using namespace std;
const int MAX_N=1e4+1;
const int INF=2e9+1e8;
int dp[MAX_N][2];
int n;
vector<pair<int,int>>g[MAX_N];
int j;
void reset()
{
    for(j=1;j<=n;++j)
    {
        dp[j][0]=0;
        dp[j][1]=-INF;
    }
}
void dfs(int u,int par)
{
    int sum=0,cur;

    for(auto [v,edge]:g[u])
    {
        if(v==par)continue;
        dfs(v,u);

        sum=sum+max(edge+dp[v][1],dp[v][0]);
    }

    for(auto [v,edge]:g[u])
    {
        if(v==par)continue;

        cur=dp[v][0];
        if(edge+dp[v][1]>cur)cur=edge+dp[v][1];
        dp[u][1]=max(dp[u][1],sum-cur+edge+dp[v][0]);
    }
    dp[u][0]=sum;
}
signed main ()
{
    ios_base::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);
    cin>>n;
    for(int i=1;i<n;i++)
    {
        int u,v,c;
        cin>>u>>v>>c;
        g[u].push_back({v,c});
        g[v].push_back({u,c});
    }
    int ans=0;
    int r;
    for(r=1;r<=n;++r)
    {
        if(g[r].size()==1)continue;
        reset();
        dfs(r,0);
        ans=max(ans,dp[r][0]);
    }
    cout<<ans<<"\n";
    return 0;
}

Compilation message (stderr)

beads.cpp: In function 'void dfs(int, int)':
beads.cpp:35:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   35 |     for(auto [v,edge]:g[u])
      |              ^
beads.cpp:43:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   43 |     for(auto [v,edge]:g[u])
      |              ^

• Subtask 1: 0 / 13
• Subtask 2: 0 / 15
• Subtask 3: 0 / 29
• Subtask 4: 0 / 43